Chronic Lymphocytic Leukemia (CLL) presents a variable clinical course, making accurate prognostic markers essential for guiding patient management and therapeutic strategies. Among the most critical biomarkers is the mutational status of the Immunoglobulin Heavy Chain Variable region (IGHV). Today, SeqOne proudly introduces SomaHemato, a comprehensive hematology analysis application on the SeqOne Platform, featuring a powerful module engineered for accurate and reliable IGHV mutational status determination for CLL.

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The Unmet Need: Why Accurate IGHV Status Matters in CLL

The IGHV gene segment is a core component of the B-cell receptor (BCR). Whether this region is mutated (differing significantly from the germline DNA sequence) or remains unmutated is a key determinant of CLL behavior:

  • Unmutated IGHV (U-IGHV): Defined by ≥98% identity to the germline sequence, U-IGHV status typically signals a more aggressive disease, often requiring earlier treatment and associated with a less favorable prognosis.
  • Mutated IGHV (M-IGHV): Defined by <98% identity to the germline, M-IGHV status usually indicates a more indolent form of CLL and often predicts better responses to specific therapies.

Determining this status accurately is essential for risk stratification and guides vital treatment decisions, particularly with the rise of targeted therapies like BTK inhibitors. However, reliably analyzing IGHV status, especially using common short-read Next-Generation Sequencing (NGS) protocols (e.g., 2x150bp), poses significant technical hurdles. Reconstructing the full variable (V) gene segment accurately is critical for homology assessment, but this can be challenging with fragmented reads.

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SeqOne's Innovation: SomaHemato for Optimized IGHV Analysis

The SomaHemato IGHV Mutational Status module, integrated within the SeqOne Platform, is specifically engineered to overcome these challenges and deliver trustworthy results from capture-based NGS data. It has been validated for both 2x250bp and the more common 2x150bp read lengths used in many clinical labs.

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How SomaHemato Delivers Precision:

  1. Robust Clonality Detection: Leveraging the power of the VIDJil engine, SomaHemato accurately identifies the dominant B-cell receptor rearrangements (clones) within the sample.
  2. Specialized Full-Length V-Gene Reconstruction: This is a cornerstone of SomaHemato. SeqOne developed a proprietary reconstruction algorithm optimized to assemble the complete V-gene sequence for relevant clones. This unique capability ensures accurate germline homology calculation even when working with shorter reads (like 2x150bp common on platforms such as NovaSeq), a frequent limitation for other methods.
  3. Comprehensive Analysis with IMGT/Arrest: Reconstructed V-gene sequences are analyzed using the internationally recognized IMGT/Arrest system (Note: SeqOne is developing an integrated internal solution for enhanced robustness) to determine:
    • Percent Identity: The core metric for classifying status as Mutated (<98%), Unmutated ( ≥98%), or Borderline (typically 97-98%).
    • Productivity: Assessing if the rearrangement can produce a functional protein.
    • Subset Classification: Identifying prognostically significant stereotyped BCR subsets, such as Subset #2 (often associated with higher-risk disease) and Subset #8, providing deeper biological insights.
  4. Clear Classification & QC: SomaHemato provides an unambiguous status for the dominant clone(s): Mutated, Unmutated, Borderline, Polyclonal (if no clone exceeds 20% frequency), or Non-Conclusive if essential quality control (QC) checks fail. Strict QC measures include minimum read counts for the clone (warnings <50 reads, errors <20 reads) and V-gene reconstruction completeness (warnings for any missing bases, failure if ≥ 30nt are missing).

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Expert Validation:

The development and validation process involved close collaboration with leading clinical hematology experts.

“For laboratories analysing the IGHV mutational status of CLL in NGS, SomaHemato represents a major advance. We have validated its performance and observed remarkable concordance with Sanger sequencing, even using short-capture data (2×150 bp). It enables reliable determination of IGHV mutation status in CLL, while providing the detailed information essential for clinical interpretation of pre-therapy assessments - all integrated directly into our routine sequencing workflows.”

Yannick Le Bris, PharmaD, PhD - Head of Molecular Hematology, Nantes University Hospital, France

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Proven Performance: Validation Highlights

SeqOne has rigorously validated the SomaHemato IGHV module, using samples provided by Nantes University Hospital among others. Our internal validation study, performed on a control cohort of 55 CLL samples sequenced using a 2x150bp protocol, demonstrated the platform's accuracy and reliability.

  • Exceptional Concordance: For all samples meeting the minimum coverage requirements necessary for conclusive analysis, SomaHemato achieved 100% accuracy in determining the IGHV mutational status (Mutated, Unmutated, Borderline) compared to the gold-standard Sanger sequencing method.
  • Accurate Subset Identification: This 100% concordance extended to the identification of clinically relevant subsets for these conclusive samples.

See illustrative data below showing the strong correlation between SomaHemato and Sanger homology results across the cohort

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Validation data demonstrates high concordance between IGHV homology determined by SeqOne's SomaHemato (NGS) and Sanger sequencing across a 55-sample cohort (2x150bp). Points represent individual samples categorized by Sanger status. The analysis confirms 100% agreement in mutational status and subset classification for samples meeting analysis quality thresholds.

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Why Choose SeqOne's SomaHemato?

  • Accuracy Even with Short Reads: Overcomes common NGS limitations with specialized full-length V-gene reconstruction.
  • Reliable & Trustworthy Results: Integrated, stringent QC checks ensure high confidence.
  • Actionable Clinical Insights: Delivers clear Mutated/Unmutated/Borderline status plus prognostically relevant subset data.
  • Expert-Validated Performance: Confirmed accuracy through clinical collaborations and comparison to gold standards.
  • Comprehensive Hematology Solution: SomaHemato is part of the robust SeqOne Platform (built on SomaVar architecture), offering a suite of tools for analyzing hematological malignancies (fusion detection, low-frequency variants, FLT3-ITD, KMT2A-PTD, CNV, TP53 analysis with IARC integration [preview]).
  • Streamlined Workflow for Informed Decisions: Provides critical IGHV data within a unified platform, facilitating accurate CLL prognostication and therapy selection.

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Advance Your CLL Diagnostics with SomaHemato

The launch of SomaHemato by SeqOne marks a significant step forward in streamlining and enhancing the accuracy of hematological malignancy testing. By providing reliable IGHV mutational status analysis within the integrated SeqOne Platform, SomaHemato empowers laboratories and clinicians to make better-informed decisions for patients with CLL.

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